State TV released a video showing President Lukashenko arriving at the presidential palace by helicopter, wearing a flak jacket and carrying an automatic weapon.
Similar demonstrations were held in other Belarusian cities. Meanwhile in Lithuania, thousands of people – including President Gitanas Nausėda – formed a human chain from the capital Vilnius to the Belarusian border in solidarity with those protesting in Minsk.
More human chains were planned in the Estonian capital Tallinn and in Prague in the Czech Republic.
This weekend’s rally in Minsk follows the country’s biggest protest in modern history on August 16, when hundreds of thousands filled the streets. Strike action in key factories across Belarus is also keeping up the pressure on the president.
President Lukashenko insists he won the election fairly and has ruled holding another poll. On August 22 he accused NATO of “trying to topple the authorities” and install a new president in Minsk.
He said he was moving troops to Belarus’s western borders to counter a NATO build-up in Poland and Lithuania, and vowed to “defend the territorial integrity of our country”.
NATO responded by saying it posed “no threat to Belarus or any other country”, and had “no military build-up in the region”.
Alexander Lukashenko has also accused an opposition council – set up by Svetlana Tikhanovskaya to organize peaceful transition – of trying to seize power. Two of its members were questioned by police on August 21.
Russia has agreed to offer security assistance to Belarus in the case of external military threats, President Alexander Lukashenko has said.
President Lukashenko also voiced concerns over NATO military exercises taking place in neighboring Poland and Lithuania.
The news comes as the embattled Belarusian president faces mass protests over the disputed August 9 election.
Thousands of Belarusians gathered outside state television on August 15, demanding full coverage of the demonstrations.
The unrest erupted after Alexander Lukashenko claimed a landslide victory in last week’s election, the result of which has been condemned amid widespread allegations of vote-rigging.
The Central Election Commission says Alexander Lukashenko, who has been in power since 1994, won 80.1% of the vote and the main opposition candidate Svetlana Tikhanovskaya 10.12%.
However, Svetlana Tikhanovskaya insists that where votes were properly counted, she won support ranging from 60% to 70%.
As the unrest continued on August 15, President Lukashenko sought help from Russian President Vladimir Putin.
President Lukashenko said President Putin had promised to provide what he called comprehensive assistance in the event of external military threats to Belarus.
The announcement came the day after EU foreign ministers agreed to prepare new sanctions against Belarusian officials responsible for “falsification”. The US has also condemned the election as “not free and fair”.
In a joint statement on August 15, the prime ministers of three Baltic republics – Latvia, Lithuania and Estonia – “expressed deep concern at the violent crackdown… and the political repression of the opposition by the authorities”.
Latvia and Lithuania have previously said they are prepared to mediate in Belarus, provided the authorities stopped violence against protesters and formed a national council with members of civil society. They warned that the alternative was sanctions.
The Baltic leaders said the Belarusian presidential election was “neither free nor fair” and called for a “transparent” vote “with the participation of international observers”.
“The prime ministers urge the Belarusian authorities to refrain from violence against peaceful demonstrators [and to] release all political prisoners and those that have been detained,” the statement added.
Svetlana Tikhanovskaya left for Lithuania following the election after she publicly denounced the results. She had sent her children to Lithuania for safety before the vote.
Some 6,700 people were arrested in the wake of the election, and many have spoken of torture at the hands of the security services.
Amnesty International said accounts from released detainees suggested “widespread torture”.
Demonstrations have continued following Svetlana Tikhanovskaya’s call for further peaceful rallies on August 14.
Some 100 staff came out of the state television building to join August 15 protests, saying they planned a strike on August 17, AFP reports. Others have signed a letter in support of a strike.
On election day, Belarusian state channels aired the voices of Lukashenko supporters and did not cover the demonstrations. State TV later showed footage of violence to blame protesters and warn people not to participate.
Several journalists have resigned over the coverage.
A “March for Freedom” is also planned in the center of Minsk on August 16, a week after the contested election.